Expansion-engine.



w. J. WOODS.

EXPANSION ENGINE. APPLICATIONHLED Nov. 15.1915 1,281,736. Patented 0ct.15,1918

' A--s spins-SHEET 1.

WITNEssESs mfG/ENTOR. /41 VV. J. woas I v BYv l w H/s ATTORNEYS.

W. J. WOODS. f I EXPNSION ENGINE.

"APPLICATION FILED Nov. I5, |915.

1,281,736. 'f Patented Oct. 15, 1918.

2 SHEETS-SHEET I?.

/1/5 ATTRNE Ys.

W. J. WOODS. EXPANSION E NGINE. APPLICATION mso Nov. 15. |915.

Pated 001.15, 1918.

-SHEET 3- WITNESSES.- df., .wm

IN1/EN TOR. W. x/

WMZ?

/1/5 ATTORNEYS.

'limi-TED srArEs PATENT oEE-ioE.

Wrnnn i. Weens, or BERKELEY, osmronms, Assis-Non or THREE-rounrns ro FRANK H. sEAnLs, or BERKELEY, CALIFORNIA.

EXPANSION-ENGINE.

ieeiyrs'e.

Patented oet, is, wie.

Application led November 15, 19l5. Serial No. 61,449.

To all ywhom t may Concern.'

Be it known that I, WILLIAM J. WOODS, a

'citizen ot the United. States, and a resident to provide engine for The invention possesses other advanta-y geous features, some of which, with the foregoing. will he set 1forth` at length in the fol-` lowingA description, whereI shall outline in full that forni 'of the invention which I have selected "for illustration in the drawings accompanying and forming part of the present specification. In said drawings I have shown only one specific form of my invention, but it is to be understood that the invention is not limited to such form, since it may be embodied iria multiplicity ot' forms, each being a species of my invention.

Referring' to said drawings:

Figure 1 is a somewhat diagrammatic representation ot one form of refrigerating apparatus or my invention, part thereotl being shown in section,

Fig. 2 is an elevation, partly diagrammatic, ol one foi-mot liquetying 'apparatus ot my invention, part thereof being shown in section.

Fig. 3 is a longitudinal section through the cylinder of the expansion engine oi my invention which also serves as an air com- "presser,

Fig. 4.-

a similar view of'a modified form of the device shown in Fig. 3.

rl`he c vcle of operations which I employ in the retrigcrating process, consists in compressing air, coolinir the compressed air, admitting the cool and compressed air to a c ijlluder and allowingit to expand against. i: -piston doing 'external and internal work, whereby it .is fui-ther cooled, passing .the cooled air through a refrigerating' coil and conductingr it back to the compr ssor where ii is again comprcsscd and passing it backl thi'UluLh the saine c}' 'lc of opcratimis. The

advisable, however,

external work done by the expanding air is employed to assist in drivingthe circulatingl compressor.

In the liquefying cycle, the air passing; into the expansion engine passes in one direction through' an intercooler, through 'which the colder air from the expansion engine passes in the opposite direction. The tivo streams of air are kept apart so that they do not mix, but they are in thermal communication, the colder air acting to reduce the temperature of' the warmer compressed air, so that when suchv air expands in the cylinder of the engine, its temperature isgreatly reduced. As the air is continuously circulated through the system itsr lower temperature is continually reduced I havevfound it in some instances, to Withdraw air from the liquefying cycle previously described and to subject this air to a greater pressure than that which olr tains in the above liquet'ying c vcle in order, to facilitate initial liquefaction. This air is withdrawn from the cycle at a point of low temperature, so that the removed air is substantially dry, the greater proportion of the moisture having;- been frozen therefrom.

I shall irst describe the retrigerating `apparatus shown in Fig. l. This apparatus comprises an air compressor '12, which l have termed the circulating compressor. The compressed air from the compressor-'2, the temperature ot' which is raised by the compressingaction, passes through the cooling coil 3, which is suitably cooled externally by dripl'iing; water or other means, so that heat is extracted from the air as it passes through. The cooled compressed air then passes through the conductor 4 to the inlet sideof the expansion engine 5. where its inflow into the cylinder G is controlled by the inlet -valve 7. The compressed air expands and docs work in the cylinder h v driving' the piston 8, whereby its temperature is iurther reduced and the cold expanded air passes through the outlet port., which is controlled hy th(l valve il, through the refrigcrating' coil 12 and hack to the inletsidc oi the circulating1 compressor Q. 'lhc valve stems extend through tubes l0, which arroi such lcnirth that thel packing nuts which close the ends of thc lobes lie cxtcrnally ot' the hcat insulating coveringlr with which the cylinder is invariably surroinulcd. ln the until liquefaction occurs.

Sor. teeil conipreeor ie operatori onlyy for; iort tnn* "lie infringot the .e n iii oicntly cnnr..

. i 4.l k Y lo eonnciferl no tlu i expansion erigir i ,of/rer riereio'petl in Je eininioyeel to fr..

25 in driving con. or. The two i l.. rzoini'non errinl cui 'let wl i, 'init AVnv siii' or 1 he pieton 3 no riferire., n o coi meeting tl'ie intef .e with tlic cyril, adiacenti the inici: to lie circn:itirngn conntension Thienrrengenient is rnicinliie liey dry nir is the coi-itinnoi .siiceeeer i therein es loi :i onreine eintioi n'i'nen greatly increiise the and. which render lille 1 opernt 1 ill.

concilitionra.

l. by

iilieorlier ierelir raising? e tein'ieintnre nnrl lowering the. ei'ciency or llie cycle. The

tenor turc rliicli obtains in tlie cylirnler prei tlic coirl nii; tl

inn-s heretofore resulted in the Y the ulniceu'inj oilunil pieton tiraittlsc engine lite become ineiliirl inoperzitire. accordance with LntionQ in'riinge the 'ii' :t ni. zrurl pienier which if lient' insuin n'liicli winiunion rent (lefeirnierl in/'thc eoininnnienteri to ed an will not ireeze tlie'p' in 'ringe in ler 3 ne torino-,rl oi two the ' nlionlfi lie frontier tlnin llio volume of the er.

oer'ntirni or iique'linetion .is very ot' lient insulating material. TheA piston 8 :le formed of two parte 8-8b securely fantenerl together. The piston part 8f 'formed of any suitable material and carries the pie'- ton rings 1'4" and the piston port?" is formeti oi: wood or other heat non-conducting matew rial. The piston part 8 is always dispos/eri. within the cylinder part 6a .and docs not .more into Contact with the cold cylinder'pzirt Gb, which part constitutes the vexpansion (slumber. The wood piston part 8*,ivl1ich is Secured tothe piston part 8a by 'tlie rod (l5, ie inefable freely Within the cylinder of tl expansion chamber enti forms e wood piston iigrziinnt which the compressed air expan fire wood piston is of slightly liess dialnet than the cylinder7 so that it does not fricM tionnlly engage the wall thereof und is; scpii.d rated from the will by n thin film of nir, The wood piston is oit' Such length with reepect to the length of the expansion chamber :iurl tile stroke of the piston, that :i port-ion of it al-i'uye lies Within the cylinder part ti, thereby allowing4 only the thin ilni of the cold air to come in Contact with the. Warm .section (3 of the cylinder, The lubricating oil is thereby prevented from freezing and of time high elliriency. The cylinder portion (3b to be eorerefl exteriorly with iront inrnilntingi nniterinln so that the lient from the Surrounding; irtnioepliere is not absorbed liv i i illien fle-Si nine, tlic expansion. engine andv tire eireulnting' compressor muy be embotlieri in n nincliine employing one cylinder, one end .being used :is tlie expansion engine :intl the other :is tlie compressor. The piston unil crlimler are constructed ne; heretofore forth with the mlrfeption that the cylinder is closed et it,` lower enrl ln' u liencl 18 through which the pieton roel passes and in which tlie ronipressor inlet :intl outlet valves 2i anni :52 nre nrriinged. Thin construction is filionn in Figs. il :nul -l-. For refrirei-utili.r gio tlie xroluine ot' the nir compr pension engine on :ir-count of llie grenter lensity of the nir ns it expande in the c \'lin-- (ler of tlie expansion engine. To :ur'oinlilisli this rlil'lerence in rupneil'y nnil still einliorlr ilie two nieclninisnis in one unit, llic con-A Htrurtion eliown in Fig. l is exnplo \'e .l. The construction shown in Fig'. 1%, however, irs operative Without eontruveninggj tliiS state nient und in .sui-li construction the preesnrc on expansion is reduc/eil below atmosphere or lielov: the loi' preaeurc of the cycle. ,ln

this construction (Figiw l) :in exteneicon 723 oi the woorl piston 5% n'liieli of lesse-r dinineter tlnin the piston. extends throng-li o stui ingr liox T24- iir 'ringed in the upper head of tlic rjfliinler. thereby reducing the volume o'i the nir expansion cylinder.

.ln Fig. 2 here shown an air iiquei"L engine nrnjf lie operated for long periode lili' i. il li tion apparatus. In apparatus 4of this type', the expansion engine cylinder is arranged horizontally, instead of vertically as in the refrigerating apparatus, so that the liquid will not flow down between the wood piston and the cylinder walls to the piston rings. In the liquefaction apparatus the compressed air from the cooling coil 3 passes through an intercooler 55 before it enters the expansion engine and the cold air from the expansion engine passes through the intel-cooler in the opposite direction. In this manner, the low pressure exhaust air 'from the engine will be warmed to, or near to, the normal temperature and the high pressure air fromthe compressor will be cooled down to near the temperature of the exhaust from the engine before it renters the cylinder of the engine to be further cooled by expansion, until by repetition 'of this stepping down process the temperature may be reduced to any degree of cold until liquefaction occurs. Liquet'action occurs in the cylinder of the expansion engine and also in the high pressure coils of the intercooler and the liquid formed in the intercooler flows to the engine cylinder' and that liquid and such as is formed vin the engine, drains through the outlet port into the vessel 56 whence it may be withdrawn at pleasure.

The intercooler comprises a casing 57 at the opposite ends of which are-arranged closed heads 58 which are connected by tubes 59. The incoming compressed air flows through the tubes and into the engine and the. cold expanded air passes through the casing 57 and around the -outside of the tubes. The space between the tubes is preferably filled with porous heat conducting material, such as wire screen 81, so that the two air streams are in close thermal coinmunieation. The, space between the tubes and the casing is filled with a heat insulat- 'ing material S2 which is arranged to cause the/exhaust air to pass among the tubes, instead ot' straight up. The intcrcoolcr, the

liquid chamber and the engine exhaust and supply pipe are always covered with a thick covering ot heat insulating material to prevent the access of external heat thereto, and the tubes through which the engine Valve stems pass are made of such length that the packing nuts occur outside of the in*- sulation. In air liquefaction apparatus, the` capacity of the circulating compressor should be four times the capacity of the ei;-

cylinder formed of two thermally insulated cylinder parts,a metallic piston slidable iu one cylinder part and a block of heat insulating material secured to the piston and slidable in the other cylinder part, the eX- pan'sion of the air occurring in said second'y cylinder part.

2. In an apparatus of the character de scribed, an expansion engine having a, cylinder formed of two thermally insulated parts, a piston provided with piston ri slidable entirely in one cylinder part, and a block of heat insulating material ozt less diameter than the cylinder attached to the piston and extending into the second cylinder part. v

3. In an apparatus of "the character described, an expansionl engine having a cylinder, a ring of heat insulating material dividing said cylinder into two parts, a metallic piston slidable in one of said part only, and a block of heat insulating mater-iai secured to said piston and extending' into the other part, said block being of such length that it does not move entirely into said irs'; cylinder part. 4

4. In an apparatus of the character described, an expansion -engine havii` t cylinder, a ring of heat insulating material dividing said cylinder into two parts, metallic piston provided with pistou rings slidable in one of said parts only, a block ot heat insulating material secured to said piston and extending into the other cylinf'ler part, the length of said block being such that on the stroke of the piston, it is not entirely withdrawn from said second cylinder part.

In testimony whereof, I have hereunto set my hand at San Francisco, California, this Sth day of November, 1915.

IVILLIAM J. VUDS.

In presence of 'I-I. G. PRosT. 

